How much of our traffic is people just passing through?

Due to West Hollywood’s location, we get a lot of pass-through drivers. This fact may discourage traffic-relief efforts, if we suspect that pass-through traffic will overwhelm anything we can do and quickly fill up any new capacity. This fact may also make trips generated by proposed new real estate developments seem insignificant relative to current and future pass-through traffic. So the quantity of pass-through traffic is important because it can influence the City’s decisionmaking.

One available estimate

As part of the work on the General Plan, a consultant developed a statistical model of the city’s traffic. That model suggests that only 25% of West Hollywood traffic is pass-through traffic. 25% is an average across all hours and days. It would probably be much higher during the weekday rush hours, but balanced out by the people coming here to shop, eat, and play on weekends and at other weekday times.

Most people who hear that number think it’s way too low, but, to the best of my knowledge, it’s the only available estimate.

Why it may not matter after all

Even if pass-through traffic is actually a much larger share of our traffic, there are three possible reasons why it might not discourage traffic-relief efforts:

Even if the estimate is off by a factor of two (50% instead of 25%), that still gives us influence over half of our traffic. We could think of it as a “tax” on our efforts, but if we get to keep 50% of the benefits it’s still worth the labor.

The way traffic congestion works, each additional driver causes more delay than the driver before them. A relatively small change at the margin in traffic volume or capacity can have a surprisingly big impact. So we don’t have to be able to influence 100% of the traffic to have an impact.

There are times of day and days of the week when pass-through traffic is lower and our street network is not maxed out. It might be easier to see the impact of traffic-relief efforts at those times.

Short answer: 25% (estimated)|
Due to West Hollywood's location, we get a lot of pass-through drivers. This fact may discourage traffic-relief efforts, if we suspect that pass-through traffic will overwhelm anything we can do and quickly fill up any new capacity. This fact may also make trips generated by proposed new real estate...

DavidWarrendavid_warren@post.harvard.eduAdministratorWeHo by the Numbers

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reports using data to explore city government policy, performance, and community issues. Focused on West Hollywood (WeHo), Beverly Hills, Culver City, Los Angeles, and Santa Monica. Researched and written by David Warren as a private citizen. This is not a government website.